Ladders are conventionally utilized to provide a user thereof with improved access to elevated locations that might otherwise be inaccessible. Ladders come in many shapes and sizes, such as straight ladders, straight extension ladders, stepladders, and combination step and extension ladders. So-called combination ladders may incorporate, in a single ladder, many of the benefits of multiple ladder designs.
Ladders known as straight ladders or extension ladders are ladders that are conventionally not self-supporting but, rather, are positioned against an elevated surface, such as a wall or the edge of a roof, to support the ladder at a desired angle. A user then ascends the ladder to obtain access to an elevated area, such as access to an upper area of the wall or access to a ceiling or roof A pair of feet or pads, each being coupled to the bottom of an associated rail of the ladder, are conventionally used to engage the ground or some other supporting surface.
In certain industries, such as in the telecommunications industry, ladders are used to access overhead cables or utility lines (e.g., cables or wires used for telephones, cable television, etc). In such cases, the ladders are sometimes supported at their upper ends by a utility pole or other vertical structure. In some situations, the upper end of the ladder is actually supported by a utility line extending generally horizontally between adjacent utility poles or towers. In such cases, the ladders have conventionally been fitted with “cable hooks” or “strand hooks” which are attached to the top of the ladder and simply hook over the top of the utility cable. The top of the ladder, thus, rests against and is supported by the horizontally extending utility cable. However, while the cable hooks generally engage the utility cable to provide support to the ladder, if the ladder shifts or tilts relative to utility cable (e.g., because of unstable ground or because of the user of the ladder leaning out to far to the side and causing the loading on the ladder to become unbalanced), one or both of the cable hooks may disengage the utility cable such that the ladder loses support and stability. This obviously creates a dangerous situation for the user of the ladder.
Some efforts have been made to provide an engagement device that provides additional security over traditional cable hooks. For example, U.S. Pat. No. 7,219,766 issued to Deuer on May 22, 2007 (the disclosure of which is incorporated by reference herein in its entirety), describes a “mid-span fall protection system” for ladders. The Deuer patent describes cable hooks, with one of the cable hooks having a latch member pivotally coupled therewith. The latch functions in conjunction with the cable hook, similar to a gate of a carabineer. When a utility member pushes upward against the latch member, the latch member is displaced permitting the utility cable to pass by. The latch member then closes (being biased by a spring toward the closed position) to capture the utility cable in an area defined by the cable hook and the latch. When it is desired to release the utility cable, a user pulls on a line tethered to the latch member to keep the latch member open while lifting the ladder to displace the cable hooks away from the utility cable. In another example, U.S. Pat. No. 5,054,581 issued to Henson on Oct. 8, 1991 (the disclosure of which is incorporated by reference herein in its entirety) describes a device that attaches to two vertically adjacent rungs of a ladder and then provides a single point attachment to a utility cable.
Also, recognizing the potential for instability in ladders in various circumstances (such as the above mentioned “shifting” of the ladder), and in an effort to improve safety of ladders generally, some efforts have been made to provide a safety line for coupling with a user's harness to help secure a user to the ladder in case of an accidental slip or fall. For example, the Deuer patent discloses a rope that is coupled to a cross-member extending between the two side rails of the ladder. An “auto-latching/locking” mechanism is coupled with the rope which requires manual release for removal. Such an auto-latching mechanism is described in U.S. Pat. No. 5,855,251 issued to Deuer on Jan. 5, 1999 (the disclosure of which is incorporated by reference herein in its entirety).
However, such proposed solutions have not necessarily proved to be entirely successful and there is a continuing desire in the industry to provide improved functionality of ladders while also improving the safety and stability of such ladders.